Method of preparing weldable ferrous members having high carbon faces



April J. w. STEINMEYER 2,439,637

METHOD OF PREPARING WELDABLE FERROUS MEMBER HAVING A HIGH CARBON FACEFiled Nov. 6, 1943 INVENTOR ATTORNEY Patented Apr. 13, 1948 METHOD "OFmmmnmo wnmmnnn maninoos MEMBERS HAVING iii-1GB cannon John rstteinmeyer,Berr'zick, 11 2a cassjgnor to American Carganil Foundry *Gompanx, NewYork, 'fY., a *eorporation of New Jersey xflpplicationNoyember 6,1943,'-; Serial1No.: 509,241

5Elaiins. (ones-19) This invention relatesrto-a weldable metal-anem-Joer -;and the imethod of ,preparation in {general rand-in particular-toahomogeneousmember com.- posed of l weldable and nomweldablmportions.

It t-has been :almost .impossible in the past "to weld, certain types ofmetal -.together due -,-to the high acarhon--content of portionsot ithemetal. This has been @found to Joe -particularly -:itrne in the.weldingof armor plate in which theireenter and: back portions are-.formed of a i-relatmely i-low carbonsteel, while the face 'or outergportioniis composed a of a I comparatively high ear-hon l-steel.sAtt6mpl3S -1J0maSkOI pI'OtECUthEIOW"(251213011fitefil plate 1 prior atooarburizing have :i-n t-he past i-re- 'sultedrin failure since noeffective --masking -.-arrangement had been devised whiehywonldwithstandthe thigh heat and 1 prevent :passage :of carboninto theplate at thearea where a weld was to be made. It is "an object, therefore, of thepresent invention to producea homogeneonsiweldable member having partslformed-of non-weldable materialgradually merging into a weldablematerialin the areas to be welded. p

A further ohjeotnof theinvention 51S athe prnduction of, azmetalmember-of relatively i'lQW 'carbon contentonto which is ;,p1 aced =agproteetive (non-ferrous imetaly 'coatin g in theareazto beawelded andprior to 1carburization. of thewmember.

A still further object of the intention issthe production "of ;ahomogeneous :weldable imetal member; havin aanon -weldable:ace;portiomgrad; ually mergingintoi a-weldable :fiace mention :snifi- .cient ly rfarfrom the 1 area to -.be Welded in cord-er that it may'betbeyond-therdangerons heat zone of the weld. n

'These and other objects :of {the invention Wlill be apparent {topersons skilled tin ath-esart from 31E, study 1 of :the followingdescription sand accompanying-drawingsin which Fig. 1 Eis an-se1ev,ational view disclosing tithe manner of applying theprotectiveccoating;

.Fig.".2risian ;.elevational view of a part of the plate disclosing therelation of the protective coating and hard faceafter -thecarburizingtreatment;

Fig. 3 is a similar view showing=the plates prepared for weldin and Fig.4 is'asimilar view 'showing the plates welded together. i

eReferring-now to the drawing-sin detail dtiwill be seen that the metalmember 2, Whichsin the present instance is of aferrous material having acarbon contentbetween .05'-percent and .3 percent, *has an areathereofadefined between loose protecting strips .4 and-:5. ilIhei-areabetween the loose protectingvstrips Aland 5.-is ;adaptecl to be coatedwith a non-ferrous material, such as cop- :per, sprayed or other-wiseapplied from "nozzles 6, 8, l0 and I2. As clearly shown the ma'terialdischarged from the nozzles defines cones as ini2 'dicatvedtbyrlineandidash. importionioif the mariterial iomning the .discharge cone {ofnozzles .6 and i2 will. strike Y the adj acent protecting strips l5tandi4, while .theiremainder ,Willdepositia coatingion, platejextendingiromthe edges of plates jeand l to tpoint M. The materialdischarging j'frommoztlellwill cover antareavextend-ing from point Hi topoint l8, whileethat discharging from ,nozzlejn .willextendifromtaipointifi to a point 22. By. arranging, the nozzles asshown the areas .of plate 2 Vbetweenstrip-Aand point Y22 and between.tstriprfi ,and point :LG will receive far-single coating of.non-ierrous material. The areas of {plate 1 between points ,and-ifl-iand l 8: and .22 will .receive \two "coats f men-ferrous.material, while the area between -points lo -and '20 will receive-three coats of r-rmater-ial, rthat Lis tone. coat trom'lnozzlex,one..coat'from nozzle |-0,-.and:-a half coatcreaching to :point l4lflrommozzles --and l2. :Thevarious coats: may. beyapplied to plate 2either by simultaneous operation of Tthe nozzleseortby successivepassages otarsingle ,nozzle or-Mot nozzles arrangedvin pairs -the: main:idea-ebeingttordeposit 1 aa 'non-ferrons :materialon 1 plate :2 a so as.to have side :edges of A a relatively thin deposit increasing.in-thiokness toward theoenter. =It:iS' WE1-1=kHOWn vthatsprayed-tmetal-is more-:01: less porousand; raccordingl-ytit is neeessarytinorder to tully protect ,.pl ate .-.2 at.-the ,altea toibe=weldedfarther-sprayed metal to increase to a suificient thickness topret-venty assage or carbon into-platez.

eAfterrdepositlomof'the non-.ferrouscoating'r3ll, iasiiiustdescliihedgthegplate tisggiven a icarburizving treatment iin -.-whichthei-plate isusubjected :to high temperaturewin :the :presenceofwsuitablercarrbon deposit. E'During wthis :earburizing treatment theplated will.absorbcarbon-through the surface exposed .to the rcarbon:material. EI-Iowever, :.due to the application of thenon-fferrousecoating 3ll, carbonzcannotzreachvthe plate inc therareas:which nareifullyazprotected iby :ztwo or more passages j ofith'ezspray. 3331185110 the porosity otthe metal'spr-ay tinttheiareaszoffisinglec'thickness, somecarbon will :passtthreugh that is, v-inthe areas defined be- Ab tw emprotectingstrip 4 and point :22 and Yproln'gdfi oftthe-carbon content-adjacent the surface '-o'fplate -2.Suc-h'tapering action'is clearly-"shown in Figi2' which:is takemfromanetchedisection of aiplate. les clearly's'hownfithe area "32 of highearbon eontent disappears at a, point-3 4 "slightly 1x55 inward of thearea protected by the-singlethick- 'ness of non ferrous metal. "In thecarburizing 'trea"tment given-plate?2in'an "actual "test "the carbon'contentpf areai32 ranged above i'l5 percent -and, therefora was of thetype "of "ferrous" metal 60 considered non-Weldable. As illustrated inFigs.

3 1 and 2 the protective coating has been shown as applied to anintermediate part of plate 2, but

it is to be understood that it may also be applied to an edge portion orto any other portion of the beveling the edges, such as at 36, Fig,3,and by.

removing at least a part of the non-ferrous coating from an area 38adjacent the trimmed edges. The point at which the plates are beveled,that is, the distance between the bevel and the point 34 at which thehigh carbon surface merges into the low carbon plate, is predeterminedinaccordance with the thickness of plate and the amount of weld. metal'40 to be applied, that is, the distance is so chosen as to prevent thedangerous heat zone, as indicated by outline 50, from reaching the highcarbon metal. In this way chill cracks, etc., are eliminated and astrong weld is obtained.

It is to be understood'that the distance between protecting strips 4'and 5, which are 'mere- 1y laid on plate 2 and later removed, may bevaried as may be the distance between the nozzle positions and betweenthe nozzles and plate to thereby obtain different layer deposits on theplate and different widths of protectivecoating. The arrangement ofnozzles and area protected is, of course, selected so that the areareceiving the greatest thickness of deposit will appear at thepoint atwhich weld metal will later be deposited. It is also important that theareas receiving the single coating of non-ferrous material should besufiicien'tly great as to obtain the proper gradual tapering of the highcarbon surface toward the area to be welded. It will be obvious alsothat non-ferrous materials, other than copper, may be used, as well ascertain nonmetallic substances which are capable of withstanding thehigh carburizing temperatures while remaining impervious to passage ofcar bon.

While the production of the homogeneous weldable plate member has beendescribed more or less in detail, it will be obvious to persons skilledin the art that various modifications in procedure and choice ofmaterials may be made and all such materials and choices arecontemplated as will fall within the scope of the appended claimsdefining my invention.

What is claimed is:

1. The method of producing a weldable ferrous-metal member having anon-weldable high carbon face and a weldable low carbon centercomprising, spraying non-ferrous metal onto a portion of a low carbonmember in successive layers of decreasing width'to form a protectivecoating having a relatively thin edge portion gradually merging into amaterially thicker portion, subjecting the member to a carburizingtreatment to produce a high carbon face which gradually disappearsbeneath the protective coating substantially in accordance with thecoating thickness, and removing a portion at least of the non-ferrousmetal coating to expose an uncarburized face portion for reception ofwelding metal. I

2. The method of producing a weldable ferrous-metal member having anon-weldablehigh carbon face and a weldable low carbon centercomprising, spraying non-ferrous metal onto a coating in accordance withthe thickness and porosity thereof, and removing at least a portion ofthe non-ferrous metal coating to expose an uncarburized face portion forreception of welding metal remote from the edge of the high carbon face.

8. The method of Welding together metal members including at least onemember hardenable by a treatment including a carbon absorption cyclecomprising, applying ametallic spray coat gradually increasing inthickness inwardly from at least one edge of the coat to protect aportion of the unhardened but hardenable member, subjecting the entirehardenable member to a hardening treatment including a carbon absorptioncycle thereby securing a gradual tapering away of the hardened metalbeneath the spray coat edge and substantially in accordance with thespray coat thickness, removing a portion at least of the metallic spraycoat 7 to expose an unhardened portion of the hardened member, andapplying welding metal to said unhardened portion of the hardened memberto join asecond metal member thereto. l

. 4. The method of producing a weldable ferrous-metal member havinganon-weldable high carbon face and a weldable low carbon centercomprising, spraying non-ferrous metal onto a portion of a low carbonmember to produce a slightly porous protective coating of singlethickness adjacent an edge and a protective coating of multiplethicknesses inwardly from said single layer, subjecting the member to acarburizing treatment to produce a high carbon face which graduallydisappears beneath the protective coating in accordance with thethickness and porosity thereof.

5. The method of producing a weldable ferrous metal member having anon-weldable high carbon face and a weldable low carbon centercomprising, Spraying non-ferrous metal onto a portion of a low carbonmember to form a coat of non-ferrous metal increasing in thickness anddecreasing in porosity inwardly from at least one edge thereof,subjecting the member to a carburizing treatment to produce a highcarbon face which disappears beneath the coating substantially inaccordance with the thickness and porosity thereof.

JOHN W. STEINMIEYER.

REFERENCES CITED The following references are of record in the file ofthis patent:

PATENTS OTHER REFERENCES Protective Coatings for Metals, Burns andSchick, 1939, page 197.

